function ListNode(name) {
    this.name = name;
    this.next = null
}

function combinList(headA, headB) {
    let dummy = res = new ListNode(0) // res 是暂存的头
    while (headA || headB) {
        if(headA.val > headB.val){
            dummy.next = headA
            headA = headA.next
        }else {
            dummy.next = headB
            headB = headB.next
        }
        dummy = dummy.next // dumy 指针也要变化
    }
    dummy.next = headA ? headA : headB; // 拼接完成后的后续 
    return res.next 
}